Added some fault tolerance to the inbound-to-unixserver message handoff process....

Added some fault tolerance to the inbound-to-unixserver message handoff process.  In some conditions, the unix socket will result in sigpipe (anecdotally, seen more oftenvirtualized environments).  these changes add a call to select before writing to the socket to check for socket availability and add a sigpipe handler that forces the inbound process to wait a brief period of time before trying the delivery again

git-svn-id: svn://svn.open-ils.org/OpenSRF/trunk@1901 9efc2488-bf62-4759-914b-345cdb29e865